1. Field of the Invention
The invention relates generally to reflector/refractor luminaire globe combinations and particularly to such combinations exhibiting increased utilization of light generated by controlling the angles of incidence of light rays incident on a refractor section of such a combination.
2. Description of the Prior Art
Reflector/refractor devices have long been available in the art and utilizable with a variety of lamping configurations to provide light distribution characteristics suitable for a number of lighting applications. Such reflector/refractor combinations have typically been formed of light transmissive materials such as glass, plastic materials such as acrylics, etc. Prisms and similar light altering structures are typically formed on both interior and exterior surfaces of prior reflector/refractor combinations in order to direct light from a contained lamp in a manner providing a desired level of light within a space that is to be illuminated. Reflector/refractor combinations are disclosed in a number of issued United States patents including U.S. Pat. No. 4,839,781 to Barnes et al, this patent disclosing the provision of a series of sectional zones on a reflector/refractor for reflecting and refracting light. The sectional zones of the Barnes et al reflector/refractor have formed thereon prisms having reflective, refractive or either reflective and refractive characteristics depending upon location relative to a light source, the reflective/refractive prisms and similar elements acting in combination to vary light distribution. The Barnes et al reflector/refractor, while formable from either glass or acrylic materials, for example, is preferably formed of light transmissive synthetic resin materials, such as, for example, an acrylic UVA5 or similar material such as by injection molding. The disclosure of U.S. Pat. No. 4,839,781 is incorporated hereinto by reference.
Fouke, in U.S. Pat. No. 6,027,231, discloses a reflector/refractor combination having prisms of varying kind disposed on surfaces thereof for a desired control of light generated within the interior of the combination by means of an HID lighting source. While the reflector/refractor of Fouke can be formed of either glass or plastic materials such as acrylic, the optical structure of Fouke is preferably formed of glass and the HID light source may constitute either a mercury, metal halide, or high pressure sodium lamp inter alia. Fouke also discloses prisms of differing configuration and kind useful in directing light in a desired direction. As such, the disclosure of U.S. Pat. No. 6,027,231 is incorporated hereinto by reference.
In U.S. Pat. No. 563,836, Blondel et al disclose a variety of configurations of lamp globes that are essentially reflector/refractor combinations, these lamp globes having differing arrangements of prisms, flutes and other light reflecting and/or refracting capabilities, the xe2x80x9cglobes, shades, reflectors, and other envelopsxe2x80x9d of Blondel et al being preferably formed of glass or similar light transmissive material. The prisms formed on the Blondel et al globes take a variety of forms having differing structure and light reflective and/or refractive capabilities chosen for use in particular situations for directing light in a desired direction. The disclosure of U.S. Pat. No. 563,836 is incorporated hereinto by reference.
Osteen, in U.S. Pat. Nos. 4,118,763 and 5,036,445, describes light transmissive globes used in luminaires and having prisms of differing description formed on said globes for controlling light direction and utilization, these patents being incorporated hereinto by reference. Harling, in U.S. Pat. No. 3,329,812, discloses a refractor arrangement having prismatic structures capable of directing light in a desired direction, this patent being incorporated hereinto by reference. Kelly et al, in U.S. Pat. No. 5,434,765, discloses a reflector/refractor combination intended to direct light downwardly by means of a judicious disposition of prismatic structures formed on said combination for the purpose of light control, this patent also being incorporated hereinto by reference.
The body of art developed in the lighting field as represented by the patents described above and by numbers of other patents as well as countless luminaires available in the marketplace over time have usually attempted to more efficiently utilize light generated by a light source contained, enclosed or otherwise associated with a light transmissive globe member forming the optical portion of luminaires configured according to the prior art. The present invention further intends improvement in the control of light within such globe members by directing light incident on major portions of a reflector section of such a globe member to a point or loci of points preferably located immediately above a light source such that the pattern of that light incident on the reflector section and onto an associated refractor section is similar to that light directly incident on the refractor section and emanating from the light source itself. Improved lighting control thus obtains to provide increased efficiency of light generated by the light source as well as a desired distribution of light from the luminaire.
The invention provides a light transmissive globe member having a reflector section and a refractor section enclosing a light source such as a gaseous discharge lamp and particularly a high intensity discharge (HID) lamp. Light produced by the light source emanates outwardly thereof from within the interior of the globe member toward essentially all surfaces of the globe member. That portion of the generated light emanating from lower, central and upper portions of the light source have a similar pattern of incidence on the refractor section of the present globe member. Major portions of the light emanating from the light source and incident on the reflector section, that is, at least over major portions of said reflector section, is incident on refractive prisms formed on interior surfaces of said reflector section and is refracted toward reflective prisms formed on outer surfaces of said reflector section. Light rays thereby incident on the reflective prisms are reflected back through the refractive prisms formed on inner surfaces of the reflector section and are refracted through a focal point or loci of points directly above the light source such that at least major portions of the light thus redirected from the reflector section is incident on at least major portions of the surfaces of the refractor section in a pattern similar to the patterns of that light emanating directly from the different portions of the light source and into direct contact with surfaces of the refractor section. By virtue of the similarity of angles of incidence of both direct light and redirected light onto refractor section surfaces, light emanating from the globe member of the invention can be more readily controlled for direction into space externally of the globe member to thereby increase the efficiency of light utilization generated by the light source.
It is therefore an object of the invention to provide a light transmissive globe member useful in a luminaire and having a reflector section functioning in combination with a refractor section so that light generated by a light source within the globe member and incident on the reflector section is redirected to form a pattern similar to light patterns of that light directly incident on the refractor section and emanating directly from the light source.
It is another object of the invention to provide a globe member formed of light transmissive material and useful in a luminaire for control of light generated by a light source contained within said globe member, the globe member being formed of a reflector section and a refractor section and functioning to control light direction by the reflection and refraction of light incident on the reflector section and emanating from the light source to a point or loci of points preferably located immediately above the light source such that a pattern of redirected light incident on at least portions of the refractor section is similar to patterns of light emanating from varying portions of the light source directly onto at least portions of the refractor section, thereby permitting control of light distribution and improvement of light utilization.
It is a further object of the invention to provide a globe member formed of light transmissive material for use in a luminaire for light control and having a reflector section and a refractor section cooperating to control light directed from the globe member, the reflector section and the refractor section being respectively formed with reflective/refractive prisms and refractive prisms on exterior surfaces thereof and configured to redirect light incident on at least major portions of the reflector section back into the interior of the globe member and through a focal point or loci of points and into incidence with at least major surface portions of the refractor section in a pattern similar to patterns of light emanating from differing portions of the light source and directly incident on said refractor section surfaces, thereby to control light distribution and improve lighting efficiency.
Further objects and advantages of the invention will become more readily apparent in light of the following detailed description of the preferred embodiments.